AVO reported that during an overflight of Cleveland on 4 August a field crew observed a cooling pad of lava that covered the crater floor. A thermal camera detected temperatures of the dome surface in the range of 550-600 degrees Celsius. Minor vapor and diffuse ash emissions inside the crater were noted. During 4-6 August satellite images detected slightly elevated surface temperatures at the summit and the webcam recorded very minor steam emissions at times of clear weather. A small explosion occurred at 2203 on 6 August; no ash emissions were observed in satellite or webcam images. Small steam plumes rose from the crater during 9-10 August. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Geological Summary. The beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Joined to the rest of Chuginadak Island by a low isthmus, Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 it produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.

Source: US Geological Survey Alaska Volcano Observatory (AVO)